Abstract

We have adapted the immunocytochemical technique which allows direct detection of gamma-aminobutyric acid (GABA) which has enabled us to visualize GABA-immunoreactive nerve cell bodies, fibers and terminals in post-mortem human striatum and cerebellum. A high density of GABA-immunoreactive nerve cell bodies is detected in the striatum. They are mostly medium-sized with a mean cross-sectional area of 236 ?? 80 ??m2 but some larger nerve cell bodies with a mean cross-sectional area of 547 ?? 104 ??m2 are also present. These neurons are most probably essentially spiny neurons type I and type II identified in the human striatum by the Golgi method. In the cerebellum, Purkinje, stellate, Golgi and basket cells are GABA-immunoreactive. In the dentatus nucleus of the cerebellum a high density of presumptive synaptic GABA-immunoreactive terminals surround the GABA-negative neurons. As predicted by animal studies the present results demonstrate that GABAergic neurons are widely distributed in the human striatum and cerebellum. They demonstrate also that GABA-immunocytochemistry can be successfully performed on post-mortem human tissue fixed by immersion after short post-mortem delay and that application of this technique may lead to a better understanding of pathological conditions involving the GABAergic transmission. ?? 1990.